Add test for flat node_modules structure

Author: rodion-arr

test/cli/show-local-tree-flat/command

@@ -0,0 +1 @@
+show 

test/cli/show-local-tree-flat/expected

@@ -0,0 +1,4 @@
+  @pkgjs/support-show-local(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }
+    dep1(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }
+    dep2(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }
+      dep3(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }

test/cli/show-local-tree-flat/exptected

@@ -0,0 +1,4 @@
+  @pkgjs/support-show-local(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }
+    dep1(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }
+    dep2(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }
+      dep3(0.0.1) - { "versions": [ { "version": "*", "target": { "node": "supported" }, "response": { "type": "best-effort" }, "backing": { "hobby": "https://github.com/pkgjs/support" } } ] }

test/cli/show-local-tree-flat/node_modules/dep1/package-support.json

@@ -0,0 +1,16 @@
+{
+  "versions": [
+    {
+      "version": "*",
+      "target": {
+        "node": "supported"
+      },
+      "response": {
+        "type": "best-effort"
+      },
+      "backing": {
+        "hobby": "https://github.com/pkgjs/support"
+      }
+    }
+  ]
+ }